/* column_prefs.c
 * Dialog box for column preferences
 *
 * $Id: prefs_column.c 42176 2012-04-21 16:40:14Z etxrab $
 *
 * Wireshark - Network traffic analyzer
 * By Gerald Combs <gerald@wireshark.org>
 * Copyright 1998 Gerald Combs
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <string.h>

#include <gtk/gtk.h>

#include <epan/prefs.h>
#include <epan/column_info.h>
#include <epan/column.h>
#include <epan/strutil.h>

#include "../globals.h"

#include "ui/gtk/prefs_column.h"
#include "ui/gtk/gtkglobals.h"
#include "ui/gtk/gui_utils.h"
#include "ui/gtk/new_packet_list.h"
#include "ui/gtk/filter_dlg.h"
#include "ui/gtk/filter_autocomplete.h"
#include "ui/gtk/old-gtk-compat.h"

static GtkWidget *remove_bt, *field_te, *field_lb, *occurrence_te, *occurrence_lb, *fmt_cmb;
static gulong column_menu_changed_handler_id;
static gulong column_field_changed_handler_id;
static gulong column_occurrence_changed_handler_id;
static gulong column_row_deleted_handler_id;

static void column_list_new_cb(GtkWidget *, gpointer);
static void column_list_delete_cb(GtkWidget *, gpointer);
static void column_list_select_cb(GtkTreeSelection *, gpointer);
static void column_menu_changed_cb(GtkWidget *, gpointer);
static void column_field_changed_cb(GtkEditable *, gpointer);
static void column_occurrence_changed_cb(GtkEditable *, gpointer);
static void column_dnd_row_deleted_cb(GtkTreeModel *, GtkTreePath *, gpointer);
static gboolean column_title_changed_cb(GtkCellRendererText *, const gchar *, const gchar *, gpointer);

static char custom_occurrence_str[8] = "";

enum {
  VISIBLE_COLUMN,
  TITLE_COLUMN,
  FORMAT_COLUMN,
  DATA_COLUMN,
  N_COLUMN /* The number of columns */
};

/* Visible toggled */
static void
visible_toggled(GtkCellRendererToggle *cell _U_, gchar *path_str, gpointer data)
{
  GtkTreeModel    *model = (GtkTreeModel *)data;
  GtkTreeIter      iter;
  GtkTreePath     *path = gtk_tree_path_new_from_string(path_str);
  GList           *clp;
  fmt_data        *cfmt;

  gtk_tree_model_get_iter(model, &iter, path);
  gtk_tree_model_get(model, &iter, DATA_COLUMN, &clp, -1);

  cfmt = (fmt_data *) clp->data;
  if (cfmt->visible)
    cfmt->visible = FALSE;
  else
    cfmt->visible = TRUE;

  gtk_list_store_set(GTK_LIST_STORE(model), &iter, VISIBLE_COLUMN, cfmt->visible, -1);
  cfile.cinfo.columns_changed = TRUE;

  gtk_tree_path_free(path);
} /* visible_toggled */

/*
 * Create and display the column selection widgets.
 * Called as part of the creation of the Preferences notebook ( Edit ! Preferences )
 */
GtkWidget *
column_prefs_show(GtkWidget *prefs_window) {
    GtkWidget         *main_vb, *bottom_hb, *column_l, *add_bt, *tb, *lb;
    GtkWidget         *list_vb, *list_lb, *list_sc;
    GtkWidget         *add_remove_vb;
    GtkWidget         *props_fr, *props_hb;
    GList             *clp;
    fmt_data          *cfmt;
    gint               i;
    gchar             *fmt;
    const gchar       *column_titles[] = {"Displayed", "Title", "Field type"};
    GtkListStore      *store;
    GtkCellRenderer   *renderer;
    GtkTreeViewColumn *column;
    GtkTreeSelection  *sel;
    GtkTreeIter        iter;
    GtkTreeIter        first_iter;
    gint               first_row = TRUE;

    /* Container for each row of widgets */
    main_vb = ws_gtk_box_new(GTK_ORIENTATION_VERTICAL, 5, FALSE);
    gtk_container_set_border_width(GTK_CONTAINER(main_vb), 5);
    gtk_widget_show(main_vb);

    list_vb = ws_gtk_box_new(GTK_ORIENTATION_VERTICAL, 0, FALSE);
    gtk_container_set_border_width  (GTK_CONTAINER (list_vb), 5);
    gtk_widget_show (list_vb);
    gtk_box_pack_start (GTK_BOX (main_vb), list_vb, TRUE, TRUE, 0);

    list_lb = gtk_label_new (("[The first list entry will be displayed as the leftmost column - Drag and drop entries to change column order]"));
    gtk_widget_show (list_lb);
    gtk_box_pack_start (GTK_BOX (list_vb), list_lb, FALSE, FALSE, 0);

    list_sc = scrolled_window_new(NULL, NULL);
    gtk_scrolled_window_set_shadow_type(GTK_SCROLLED_WINDOW(list_sc), GTK_SHADOW_IN);
    gtk_container_add(GTK_CONTAINER(list_vb), list_sc);
    gtk_widget_show(list_sc);

    store = gtk_list_store_new(N_COLUMN,
			       G_TYPE_BOOLEAN,
			       G_TYPE_STRING, G_TYPE_STRING, G_TYPE_POINTER);
    column_row_deleted_handler_id =
        g_signal_connect(GTK_TREE_MODEL(store), "row-deleted", G_CALLBACK(column_dnd_row_deleted_cb), NULL);

    column_l = tree_view_new(GTK_TREE_MODEL(store));
    gtk_tree_view_set_headers_visible(GTK_TREE_VIEW(column_l), TRUE);
    gtk_tree_view_set_headers_clickable(GTK_TREE_VIEW(column_l), FALSE);
    gtk_tree_view_set_reorderable(GTK_TREE_VIEW(column_l), TRUE);
    gtk_widget_set_tooltip_text(column_l, "Click on a title to change its name.\nDrag an item to change its order.");

    renderer = gtk_cell_renderer_toggle_new();
    g_signal_connect(renderer, "toggled", G_CALLBACK(visible_toggled), store);
    column = gtk_tree_view_column_new_with_attributes(column_titles[VISIBLE_COLUMN], renderer, "active", VISIBLE_COLUMN, NULL);
    gtk_tree_view_column_set_sizing(column, GTK_TREE_VIEW_COLUMN_AUTOSIZE);
    gtk_tree_view_append_column(GTK_TREE_VIEW(column_l), column);

    renderer = gtk_cell_renderer_text_new();
    g_object_set(G_OBJECT(renderer), "editable", TRUE, NULL);
    g_signal_connect (renderer, "edited", G_CALLBACK(column_title_changed_cb), GTK_TREE_MODEL(store));
    column = gtk_tree_view_column_new_with_attributes(column_titles[TITLE_COLUMN], renderer, "text", TITLE_COLUMN, NULL);
    gtk_tree_view_column_set_sizing(column, GTK_TREE_VIEW_COLUMN_AUTOSIZE);
    gtk_tree_view_append_column(GTK_TREE_VIEW(column_l), column);

    renderer = gtk_cell_renderer_text_new();
    column = gtk_tree_view_column_new_with_attributes(column_titles[FORMAT_COLUMN], renderer, "text", FORMAT_COLUMN, NULL);
    gtk_tree_view_column_set_sizing(column, GTK_TREE_VIEW_COLUMN_AUTOSIZE);
    gtk_tree_view_append_column(GTK_TREE_VIEW(column_l), column);

    /* XXX - make this match the packet list prefs? */
    sel = gtk_tree_view_get_selection(GTK_TREE_VIEW(column_l));
    gtk_tree_selection_set_mode(sel, GTK_SELECTION_SINGLE);
    g_signal_connect(sel, "changed", G_CALLBACK(column_list_select_cb), NULL);

    gtk_container_add(GTK_CONTAINER(list_sc), column_l);
    gtk_widget_show(column_l);

    clp = g_list_first(prefs.col_list);
    while (clp) {
        cfmt    = (fmt_data *) clp->data;
        if (cfmt->fmt == COL_CUSTOM) {
            if (cfmt->custom_occurrence) {
                fmt = g_strdup_printf("%s (%s#%d)", col_format_desc(cfmt->fmt), cfmt->custom_field, cfmt->custom_occurrence);
            } else {
                fmt = g_strdup_printf("%s (%s)", col_format_desc(cfmt->fmt), cfmt->custom_field);
            }
        } else {
            if (cfmt->custom_field) {
                /* Delete custom_field from previous changes */
                g_free (cfmt->custom_field);
                cfmt->custom_field = NULL;
                cfmt->custom_occurrence = 0;
            }
            fmt = g_strdup_printf("%s", col_format_desc(cfmt->fmt));
        }
        gtk_list_store_insert_with_values(store, &iter, G_MAXINT,
			   VISIBLE_COLUMN, cfmt->visible,
			   TITLE_COLUMN, cfmt->title, FORMAT_COLUMN, fmt, DATA_COLUMN, clp, -1);

        if (first_row) {
            first_iter = iter;
            first_row = FALSE;
        }
        clp = clp->next;
        g_free (fmt);
    }
    g_object_unref(G_OBJECT(store));

    /* Bottom row: Add/remove buttons and properties */
    bottom_hb = ws_gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 5, FALSE);
    gtk_box_pack_start (GTK_BOX (main_vb), bottom_hb, FALSE, TRUE, 0);
    gtk_widget_show(bottom_hb);

    /* Add / remove buttons */
    add_remove_vb = ws_gtk_box_new(GTK_ORIENTATION_VERTICAL, 0, TRUE);
    gtk_container_set_border_width (GTK_CONTAINER (add_remove_vb), 5);
    gtk_box_pack_start (GTK_BOX (bottom_hb), add_remove_vb, FALSE, FALSE, 0);
    gtk_widget_show(add_remove_vb);

    add_bt = gtk_button_new_from_stock(GTK_STOCK_ADD);
    g_signal_connect(add_bt, "clicked", G_CALLBACK(column_list_new_cb), column_l);
    gtk_box_pack_start (GTK_BOX (add_remove_vb), add_bt, FALSE, FALSE, 0);
    gtk_widget_set_tooltip_text(add_bt, "Add a new column at the end of the list.");
    gtk_widget_show(add_bt);

    remove_bt = gtk_button_new_from_stock(GTK_STOCK_REMOVE);
    gtk_widget_set_sensitive(remove_bt, FALSE);
    g_signal_connect(remove_bt, "clicked", G_CALLBACK(column_list_delete_cb), column_l);
    gtk_box_pack_start (GTK_BOX (add_remove_vb), remove_bt, FALSE, FALSE, 0);
    gtk_widget_set_tooltip_text(remove_bt, "Remove the selected column.");
    gtk_widget_show(remove_bt);

    /* properties frame */
    props_fr = gtk_frame_new("Properties");
    gtk_box_pack_start (GTK_BOX (bottom_hb), props_fr, TRUE, TRUE, 0);
    gtk_widget_show(props_fr);

    /* Column name entry and format selection */
    tb = gtk_table_new(2, 4, FALSE);
    gtk_container_set_border_width(GTK_CONTAINER(tb), 5);
    gtk_container_add(GTK_CONTAINER(props_fr), tb);
    gtk_table_set_row_spacings(GTK_TABLE(tb), 10);
    gtk_table_set_col_spacings(GTK_TABLE(tb), 15);
    gtk_widget_show(tb);

    lb = gtk_label_new("Field type:");
    gtk_misc_set_alignment(GTK_MISC(lb), 0.0f, 0.5f);
    gtk_table_attach_defaults(GTK_TABLE(tb), lb, 0, 1, 0, 1);
    gtk_widget_set_tooltip_text(lb, "Select which packet information to present in the column.");
    gtk_widget_show(lb);

    props_hb = ws_gtk_box_new(GTK_ORIENTATION_HORIZONTAL, 5, FALSE);
    gtk_table_attach(GTK_TABLE(tb), props_hb, 1, 2, 0, 1, GTK_FILL, GTK_SHRINK, 0, 0);
    gtk_widget_set_tooltip_text(props_hb, "Select which packet information to present in the column.");
    gtk_widget_show(props_hb);

    field_lb = gtk_label_new("Field name:");
    gtk_misc_set_alignment(GTK_MISC(field_lb), 0.0f, 0.5f);
    gtk_table_attach_defaults(GTK_TABLE(tb), field_lb, 0, 1, 1, 2);
    gtk_widget_set_sensitive(field_lb, FALSE);
    gtk_widget_set_tooltip_text(field_lb, 
                          "Field name used when field type is \"Custom\". "
                          "This string has the same syntax as a display filter string.");
    gtk_widget_show(field_lb);

    field_te = gtk_entry_new();
    g_object_set_data (G_OBJECT(field_te), E_FILT_FIELD_NAME_ONLY_KEY, "");
    g_signal_connect(field_te, "changed", G_CALLBACK(filter_te_syntax_check_cb), NULL);

    /* XXX: column_field_changed_cb will be called for every character entered in the entry box.      */
    /*       Consider Changing logic so that the field is "accepted" only when a return is entered ?? */
    /*       Also: entry shouldn't be accepted if it's not a valid filter ?                           */
    column_field_changed_handler_id =
        g_signal_connect(field_te, "changed", G_CALLBACK(column_field_changed_cb), column_l);

    g_object_set_data(G_OBJECT(main_vb), E_FILT_AUTOCOMP_PTR_KEY, NULL);
    g_signal_connect(field_te, "key-press-event", G_CALLBACK (filter_string_te_key_pressed_cb), NULL);
    g_signal_connect(prefs_window, "key-press-event", G_CALLBACK (filter_parent_dlg_key_pressed_cb), NULL);
    colorize_filter_te_as_empty(field_te);
    gtk_table_attach_defaults(GTK_TABLE(tb), field_te, 1, 2, 1, 2);
    gtk_widget_set_sensitive(field_te, FALSE);
    gtk_widget_set_tooltip_text(field_te, 
                          "Field name used when field type is \"Custom\". "
                          "This string has the same syntax as a display filter string.");
    gtk_widget_show(field_te);

    occurrence_lb = gtk_label_new("Field occurrence:");
    gtk_misc_set_alignment(GTK_MISC(occurrence_lb), 0.0f, 0.5f);
    gtk_table_attach_defaults(GTK_TABLE(tb), occurrence_lb, 2, 3, 1, 2);
    gtk_widget_set_sensitive(occurrence_lb, FALSE);
    gtk_widget_set_tooltip_text(occurrence_lb, 
                          "Field occurence to use. "
                          "0=all (default), 1=first, 2=second, ..., -1=last.");
    gtk_widget_show(occurrence_lb);

    occurrence_te = gtk_entry_new();
    gtk_entry_set_max_length (GTK_ENTRY(occurrence_te),4);
    g_object_set_data (G_OBJECT(occurrence_te), "occurrence", "");

    /* XXX: column_occurrence_changed_cb will be called for every character entered in the entry box.      */
    /*       Consider Changing logic so that the field is "accepted" only when a return is entered ?? */
    column_occurrence_changed_handler_id =
        g_signal_connect(occurrence_te, "changed", G_CALLBACK(column_occurrence_changed_cb), column_l);

    gtk_table_attach_defaults(GTK_TABLE(tb), occurrence_te, 3, 4, 1, 2);
    gtk_widget_set_sensitive(occurrence_te, FALSE);
    gtk_widget_set_tooltip_text(occurrence_te, 
                          "Field occurence to use. "
                          "0=all (default), 1=first, 2=second, ..., -1=last.");
    gtk_widget_show(occurrence_te);

    fmt_cmb = gtk_combo_box_text_new();

    for (i = 0; i < NUM_COL_FMTS; i++)
         gtk_combo_box_text_append_text (GTK_COMBO_BOX_TEXT(fmt_cmb), col_format_desc(i));

    column_menu_changed_handler_id = g_signal_connect(fmt_cmb, "changed", G_CALLBACK(column_menu_changed_cb), column_l);

    gtk_widget_set_sensitive(fmt_cmb, FALSE);
    gtk_box_pack_start(GTK_BOX(props_hb), fmt_cmb, FALSE, FALSE, 0);
    gtk_widget_show(fmt_cmb);

    /* select the first menu list row.             */
    /*  Triggers call to column_list_select_cb().  */
    gtk_tree_selection_select_iter(sel, &first_iter);

    return(main_vb);
}

void
column_prefs_add_custom(gint fmt, const gchar *title, const gchar *custom_field, gint custom_occurrence)
{
  GList *clp;
  fmt_data *cfmt, *last_cfmt;

  cfmt = (fmt_data *) g_malloc(sizeof(fmt_data));
  /*
   * Because a single underscore is interpreted as a signal that the next character
   * is going to be marked as accelerator for this header (i.e. is going to be
   * shown underlined), escape it be inserting a second consecutive underscore.
   */
  cfmt->title = g_strdup(title);
  cfmt->fmt = fmt;
  cfmt->custom_field = g_strdup(custom_field);
  cfmt->custom_occurrence = custom_occurrence;
  cfmt->resolved = TRUE;

  if (custom_field) {
    cfmt->visible = TRUE;
    clp = g_list_last(prefs.col_list);
    last_cfmt = (fmt_data *) clp->data;
    if (last_cfmt->fmt == COL_INFO) {
      /* Last column is COL_INFO, add custom column before this */
      prefs.col_list = g_list_insert(prefs.col_list, cfmt, g_list_length(prefs.col_list)-1);
    } else {
      prefs.col_list = g_list_append(prefs.col_list, cfmt);
    }
  } else {
    cfmt->visible = FALSE;  /* Will be set to TRUE in visible_toggled() when added to list */
    prefs.col_list = g_list_append(prefs.col_list, cfmt);
  }
}

void
column_prefs_remove(gint col)
{
  GList    *clp = g_list_nth(prefs.col_list, col);
  fmt_data *cfmt = (fmt_data *) clp->data;

  g_free(cfmt->title);
  g_free(cfmt->custom_field);
  g_free(cfmt);
  prefs.col_list = g_list_remove_link(prefs.col_list, clp);
}

/* To do: add input checking to each of these callbacks */

static void
column_list_new_cb(GtkWidget *w _U_, gpointer data) {
    gint               cur_fmt;
    const gchar       *title = "New Column";
    GtkTreeView       *column_l = GTK_TREE_VIEW(data);
    GtkTreeModel      *model;
    GtkTreeIter        iter;
    GtkTreePath       *path;
    GtkTreeViewColumn *title_column;

    cur_fmt = COL_NUMBER;    /*  Set the default new column type */
    column_prefs_add_custom (cur_fmt, title, NULL, 0);

    model = gtk_tree_view_get_model(column_l);
    gtk_list_store_insert_with_values(GTK_LIST_STORE(model), &iter, G_MAXINT,
                       VISIBLE_COLUMN, TRUE,
                       TITLE_COLUMN, title,
                       FORMAT_COLUMN, col_format_desc(cur_fmt),
                       DATA_COLUMN, g_list_last(prefs.col_list),
                       -1);

    /* Triggers call to column_list_select_cb()   */
    gtk_tree_selection_select_iter(gtk_tree_view_get_selection(column_l), &iter);

    /* Set the cursor to the 'Title' column of the newly added row and enable editing */
    /* XXX: If displaying the new title ["New column"] widens the title column of the */
    /*      treeview, then the set_cursor below doesn't properly generate an entry    */
    /*      box around the title text. The width of the box appears to be the column  */
    /*      width before the treeview title column was widened.  Seems like a bug...  */
    /*      I haven't found a work-around.                                            */
    path = gtk_tree_model_get_path(model, &iter);
    title_column = gtk_tree_view_get_column(column_l, 0);
    gtk_tree_view_set_cursor(column_l, path, title_column, TRUE);
    gtk_tree_path_free(path);

    cfile.cinfo.columns_changed = TRUE;
}


static void
column_list_delete_cb(GtkWidget *w _U_, gpointer data) {
    GtkTreeView      *column_l = GTK_TREE_VIEW(data);
    GList            *clp;
    fmt_data         *cfmt;
    GtkTreeSelection *sel;
    GtkTreeModel     *model;
    GtkTreeIter       iter;
    GtkTreeIter       new_iter;

    sel = gtk_tree_view_get_selection(column_l);
    if (gtk_tree_selection_get_selected(sel, &model, &iter))
    {
        gtk_tree_model_get(model, &iter, DATA_COLUMN, &clp, -1);

        cfmt = (fmt_data *) clp->data;
        g_free(cfmt->title);
        g_free(cfmt->custom_field);
        g_free(cfmt);
        prefs.col_list = g_list_remove_link(prefs.col_list, clp);

        /* Change the row selection to the next row (if available) or    */
        /*  the previous row (if available). If there's only one row     */
        /*  in the store (no previous and no next), then the selection   */
        /*  will not be changed.                                         */

        /* Note that gtk_tree_selection_select_iter() will trigger a     */
        /* call to column_list_select_cb().                              */

        new_iter = iter;
        if ( gtk_tree_model_iter_next(model, &new_iter)) {
            gtk_tree_selection_select_iter(sel, &new_iter);
        } else { /* "gtk_tree_model_iter_prev" */
            GtkTreePath *path = gtk_tree_model_get_path(model, &iter);
            if (gtk_tree_path_prev(path)) {
                gtk_tree_model_get_iter(model, &new_iter, path);
                gtk_tree_selection_select_iter(sel, &new_iter);
            }
            gtk_tree_path_free(path);
        }

        /* Remove the row from the list store.                           */
        /*  We prevent triggering call to column_row_deleted_cb() since  */
        /*  the entry has already been removed from prefs.col_list and   */
        /*  since rebuilding the list is not needed because the order    */
        /*  of the list hasn't changed.                                  */

        g_signal_handler_block(model, column_row_deleted_handler_id);

        /* list_store_remove below will trigger a call to                */
        /* column_list_select_cb() only when deleting the last entry in  */
        /* the column list.                                              */
        /* (This is because the selection in this case changes to        */
        /*  "nothing selected" when the last row is removed.             */

        gtk_list_store_remove(GTK_LIST_STORE(model), &iter);

        g_signal_handler_unblock  (model, column_row_deleted_handler_id);

        cfile.cinfo.columns_changed = TRUE;
    }
}


static gboolean
column_title_changed_cb(GtkCellRendererText *cell _U_, const gchar *str_path, const gchar *new_title, gpointer data) {
    fmt_data     *cfmt;
    GList        *clp;
    GtkTreeModel *model = (GtkTreeModel *)data;
    GtkTreePath  *path = gtk_tree_path_new_from_string (str_path);
    GtkTreeIter   iter;

    gtk_tree_model_get_iter(model, &iter, path);

    gtk_list_store_set(GTK_LIST_STORE(model), &iter, TITLE_COLUMN, new_title, -1);

    gtk_tree_model_get(model, &iter, DATA_COLUMN, &clp, -1);
    if (clp) {
        cfmt  = (fmt_data *) clp->data;
        g_free(cfmt->title);
        cfmt->title = g_strdup(new_title);
    }

    gtk_tree_path_free (path);
    cfile.cinfo.columns_changed = TRUE;
    return TRUE;
}

/*
 * column list row selection changed.
 *  Set the "Properties" widgets to match the currently selected column row item.
 */

static void
column_list_select_cb(GtkTreeSelection *sel, gpointer data _U_)
{
    fmt_data     *cfmt;
    GList        *clp;
    GtkTreeModel *model;
    GtkTreeIter   iter;

    /* if something was selected */
    if (gtk_tree_selection_get_selected(sel, &model, &iter))
    {
        gtk_tree_model_get(model, &iter, DATA_COLUMN, &clp, -1);
        g_assert(clp != NULL);
        cfmt    = (fmt_data *) clp->data;

        g_signal_handler_block  (fmt_cmb, column_menu_changed_handler_id);
        gtk_combo_box_set_active(GTK_COMBO_BOX(fmt_cmb), cfmt->fmt);
        g_signal_handler_unblock(fmt_cmb, column_menu_changed_handler_id);

        g_signal_handler_block  (field_te, column_field_changed_handler_id);
        g_signal_handler_block  (occurrence_te, column_occurrence_changed_handler_id);
        if (cfmt->fmt == COL_CUSTOM) {
            gtk_entry_set_text(GTK_ENTRY(field_te), cfmt->custom_field);
            gtk_widget_set_sensitive(field_lb, TRUE);
            gtk_widget_set_sensitive(field_te, TRUE);
            g_snprintf(custom_occurrence_str, sizeof(custom_occurrence_str), "%d", cfmt->custom_occurrence);
            gtk_entry_set_text(GTK_ENTRY(occurrence_te), custom_occurrence_str);
            gtk_widget_set_sensitive(occurrence_lb, TRUE);
            gtk_widget_set_sensitive(occurrence_te, TRUE);
        } else {
            gtk_editable_delete_text(GTK_EDITABLE(field_te), 0, -1);
            gtk_widget_set_sensitive(field_lb, FALSE);
            gtk_widget_set_sensitive(field_te, FALSE);
            gtk_editable_delete_text(GTK_EDITABLE(occurrence_te), 0, -1);
            gtk_widget_set_sensitive(occurrence_lb, FALSE);
            gtk_widget_set_sensitive(occurrence_te, FALSE);
        }
        g_signal_handler_unblock(occurrence_te, column_occurrence_changed_handler_id);
        g_signal_handler_unblock(field_te, column_field_changed_handler_id);

        gtk_widget_set_sensitive(remove_bt, TRUE);
        gtk_widget_set_sensitive(fmt_cmb, TRUE);
    }
    else
    {
        gtk_editable_delete_text(GTK_EDITABLE(field_te), 0, -1);
        gtk_editable_delete_text(GTK_EDITABLE(occurrence_te), 0, -1);

        gtk_widget_set_sensitive(remove_bt, FALSE);
        gtk_widget_set_sensitive(field_te, FALSE);
        gtk_widget_set_sensitive(occurrence_te, FALSE);
        gtk_widget_set_sensitive(fmt_cmb, FALSE);
    }
}


/*
 * The user selected a new entry in the format combo-box;
 *       Note: column_menu_changed_cb is expected to be called only
 *         when the user changes the format combo-box.
 * Action:
 * If no selection active in the column list:
 *    Hide 'field"; desensitize buttons.
 *    XXX: Can this happen ?
 * If a column list selection is active:
 *    1. Update the display of "field" as req'd (depending upon
 *       whether the active combo-box entry is the "custom"
 *       format type).
 *    2. Update the column_list and prefs.col_formats.
 *       Set columns_changed = TRUE.
 */

static void
column_menu_changed_cb(GtkWidget *w, gpointer data) {
    GtkTreeView      *column_l = GTK_TREE_VIEW(data);
    fmt_data         *cfmt;
    gint              cur_cb_fmt;
    GList            *clp;
    gchar            *fmt;
    GtkTreeSelection *sel;
    GtkTreeModel     *model;
    GtkTreeIter       iter;

    sel = gtk_tree_view_get_selection(column_l);
    if (! (gtk_tree_selection_get_selected(sel, &model, &iter)))
        return;  /* no column list selection [Can this happen ?]: ignore callback */

    cur_cb_fmt = gtk_combo_box_get_active(GTK_COMBO_BOX(w));
    gtk_tree_model_get(model, &iter, DATA_COLUMN, &clp, -1);
    cfmt    = (fmt_data *) clp->data;

    g_assert(cur_cb_fmt != cfmt->fmt);

    /* The User has selected a new format in the combo-box    */
    /*  (IE: combo-box format != current selected row format) */
    /* Update field widgets, list_store, column format array  */
    /*  entry as appropriate.                                 */
    g_signal_handler_block  (field_te, column_field_changed_handler_id);
    g_signal_handler_block  (occurrence_te, column_occurrence_changed_handler_id);
    if (cfmt->fmt == COL_CUSTOM) {
        /* Changing from custom to non-custom   */
        gtk_editable_delete_text(GTK_EDITABLE(field_te), 0, -1);
        gtk_editable_delete_text(GTK_EDITABLE(occurrence_te), 0, -1);
        fmt = g_strdup_printf("%s", col_format_desc(cur_cb_fmt));
        gtk_widget_set_sensitive(field_lb, FALSE);
        gtk_widget_set_sensitive(field_te, FALSE);
        gtk_widget_set_sensitive(occurrence_lb, FALSE);
        gtk_widget_set_sensitive(occurrence_te, FALSE);

    } else if (cur_cb_fmt == COL_CUSTOM) {
        /* Changing from non-custom to custom   */
        if (cfmt->custom_field == NULL)
            cfmt->custom_field = g_strdup("");
        /* The following doesn't trigger a call to menu_field_changed_cb()    */
        gtk_entry_set_text(GTK_ENTRY(field_te), cfmt->custom_field);
        g_snprintf(custom_occurrence_str, sizeof(custom_occurrence_str), "%d", cfmt->custom_occurrence);
        gtk_entry_set_text(GTK_ENTRY(occurrence_te), custom_occurrence_str);

        if (cfmt->custom_occurrence) {
            fmt = g_strdup_printf("%s (%s#%d)", col_format_desc(cur_cb_fmt), cfmt->custom_field, cfmt->custom_occurrence);
        } else {
            fmt = g_strdup_printf("%s (%s)", col_format_desc(cur_cb_fmt), cfmt->custom_field);
        }
        gtk_widget_set_sensitive(field_lb, TRUE);
        gtk_widget_set_sensitive(field_te, TRUE);
        gtk_widget_set_sensitive(occurrence_lb, TRUE);
        gtk_widget_set_sensitive(occurrence_te, TRUE);

    } else {
        /* Changing from non-custom to non-custom */
        fmt = g_strdup_printf("%s", col_format_desc(cur_cb_fmt));
    }
    g_signal_handler_unblock(occurrence_te, column_occurrence_changed_handler_id);
    g_signal_handler_unblock(field_te, column_field_changed_handler_id);

    gtk_list_store_set(GTK_LIST_STORE(model), &iter, FORMAT_COLUMN, fmt, -1);
    g_free(fmt);
    cfmt->fmt = cur_cb_fmt;
    cfile.cinfo.columns_changed = TRUE;
}


/*
 * The user changed the custom field entry box or
 *  the field entry box has been updated because a new
 *  column row with custom format has been selected.
 * If the current field entry matches that of the current
 *  column row, this is just an update because a new
 *  column row has been selected. Do nothing.
 * If the two are different, then update the column row & etc.
 */
static void
column_field_changed_cb(GtkEditable *te, gpointer data) {
    fmt_data         *cfmt;
    GList            *clp;
    gchar            *field, *fmt;
    GtkTreeView      *tree = (GtkTreeView *)data;
    GtkTreeSelection *sel;
    GtkTreeModel     *model;
    GtkTreeIter       iter;

    sel = gtk_tree_view_get_selection(tree);
    if ( ! (gtk_tree_selection_get_selected(sel, &model, &iter))) {
        return;
    }

    field = gtk_editable_get_chars(te, 0, -1);
    gtk_tree_model_get(model, &iter, DATA_COLUMN, &clp, -1);
    cfmt  = (fmt_data *) clp->data;
    if (strcmp(cfmt->custom_field, field) == 0) {
        return; /* no action req'd */
    }

    /* The user has entered a new value in the field entry box: make the req'd changes */
    if (cfmt->custom_occurrence) {
        fmt = g_strdup_printf("%s (%s#%d)", col_format_desc(cfmt->fmt), field, cfmt->custom_occurrence);
    } else {
        fmt = g_strdup_printf("%s (%s)", col_format_desc(cfmt->fmt), field);
    }

    gtk_list_store_set(GTK_LIST_STORE(model), &iter, FORMAT_COLUMN, fmt, -1);
    g_free(fmt);
    g_free(cfmt->custom_field);
    cfmt->custom_field = field;
    cfile.cinfo.columns_changed = TRUE;
}


/*
 * The user changed the custom field occurrence entry box or
 *  the field occurrece entry box has been updated because a new
 *  column row with custom format has been selected.
 * If the current field entry matches that of the current
 *  column row, this is just an update because a new
 *  column row has been selected. Do nothing.
 * If the two are different, then update the column row & etc.
 */
static void
column_occurrence_changed_cb(GtkEditable *te, gpointer data) {
    fmt_data         *cfmt;
    gint              occurrence;
    GList            *clp;
    gchar            *fmt;
    GtkTreeView      *tree = (GtkTreeView *)data;
    GtkTreeSelection *sel;
    GtkTreeModel     *model;
    GtkTreeIter       iter;

    sel = gtk_tree_view_get_selection(tree);
    if ( ! (gtk_tree_selection_get_selected(sel, &model, &iter))) {
        return;
    }

    occurrence = (gint)strtol(gtk_editable_get_chars(te, 0, -1), NULL, 10);
    gtk_tree_model_get(model, &iter, DATA_COLUMN, &clp, -1);
    cfmt  = (fmt_data *) clp->data;
    if (cfmt->custom_occurrence == occurrence) {
        return; /* no action req'd */
    }

    /* The user has entered a new value in the field occurrence entry box: make the req'd changes */
    if (occurrence) {
        fmt = g_strdup_printf("%s (%s#%d)", col_format_desc(cfmt->fmt), cfmt->custom_field, occurrence);
    } else {
        fmt = g_strdup_printf("%s (%s)", col_format_desc(cfmt->fmt), cfmt->custom_field);
    }

    gtk_list_store_set(GTK_LIST_STORE(model), &iter, FORMAT_COLUMN, fmt, -1);
    g_free(fmt);
    cfmt->custom_occurrence = occurrence;
    cfile.cinfo.columns_changed = TRUE;
}


/*
 * Callback for the "row-deleted" signal emitted when a list item is dragged.
 * http://library.gnome.org/devel/gtk/stable/GtkTreeModel.html#GtkTreeModel-rows-reordered
 * says that DND deletes, THEN inserts the row.
 *
 * XXX: For the record: For Gtk+ 2.16.0 testing shows the actual sequence for drag-and-drop to be as follows:
 *      1. Insert a new, empty row at the destination;
 *      2. Emit a "row-inserted" signal on the model; invoke any row-inserted callbacks & etc;
 *      3. Copy the source row data to the new (empty) destination row;
 *      4. Delete the source row;
 *      5. Emit a "row-deleted" signal; invoke any row-deleted callbacks & etc.
 *
 *  The code below (invoked as a consequence of a "row-deleted" signal) rebuilds
 *  prefs.col_list by iterating over the (re-ordered) tree model.
 */
static void
column_dnd_row_deleted_cb(GtkTreeModel *model, GtkTreePath *path _U_, gpointer data _U_) {
    GtkTreeIter   iter;
    GList        *clp, *new_col_list = NULL;
    gboolean      items_left;

    /*
     * XXX - This rebuilds prefs.col_list based on the current model. We
     * might just want to do this when the prefs are applied
     */
    for (items_left = gtk_tree_model_get_iter_first (model, &iter);
         items_left;
         items_left = gtk_tree_model_iter_next (model, &iter)) {

        gtk_tree_model_get(model, &iter, DATA_COLUMN, &clp, -1);
        if (clp) {
            prefs.col_list = g_list_remove_link(prefs.col_list, clp);
            new_col_list = g_list_concat(new_col_list, clp);
        }
    }
    if (prefs.col_list) {
        g_warning("column_dnd_row_deleted_cb: prefs.col_list has %d leftover data",
                  g_list_length(prefs.col_list));
        g_list_free(prefs.col_list);
    }

    prefs.col_list = new_col_list;
    cfile.cinfo.columns_changed = TRUE;
}


void
column_prefs_fetch(GtkWidget *w _U_) {
}


void
column_prefs_apply(GtkWidget *w _U_)
{
    /* Redraw the packet list if the columns were changed */
    if(cfile.cinfo.columns_changed) {
        new_packet_list_recreate();
        cfile.cinfo.columns_changed = FALSE; /* Reset value */
    }
}


void
column_prefs_destroy(GtkWidget *w _U_) {
}